Results from HF-ACTION support intensive exercise for patients with heart failure
Exercise training is safe in heart failure patients,
does not significantly reduce hospitalization or death, but is associated with
several improved clinical outcomes, even in those already receiving optimal medical
care, researchers reported at the American Heart Association's Scientific Sessions
2008. The Heart Failure and A Controlled Trial Investigating Outcomes of Exercise
Training (HF-ACTION) was presented as a late-breaking clinical trial.
The trial is the world's largest study of exercise training
versus usual care in heart failure (HF) patients, said Christopher M. O'Connor,
M.D., principal investigator and director of the Heart Center and professor of
medicine at Duke University Medical Center in Durham, N.C.
The U.S.-government-funded, randomized, Phase III trial
followed 2,331 heart failure patients (average age 59) at 82 sites in the United
States, Canada and Europe for an average of 2.5 years. The patients were randomized
to an exercise training program aimed at increasing workout intensity and duration
or to usual care, in which they were encouraged to exercise, but without any specific
program.
Researchers found no excess risk for heart attack, arrhythmia,
angina or fractures in the exercise training group.
Although exercise training of heart failure patients
was not associated with a statistically significant reduction of the primary endpoint
of composite of all-cause hospitalization and death, the prespecified secondary
analyses with adjustment for prespecified major prognostic factors revealed an
11 percent reduction (p-value = 0.03) in the study's primary endpoint and a 15
percent (p-value = 0.03) reduction in the secondary endpoint of cardiovascular
mortality and heart failure hospitalization compared to the usual care group.
"Exercise training confers clinical benefits without
excess risk for heart failure patients," O'Connor said. "There was a real question
in the literature as to whether these high-risk patients could safely attempt
exercise training and whether doctors should prescribe exercise training for these
patients outside of a highly supervised environment." Most insurance and government
health programs refuse to cover exercise training for heart failure patients because
of a lack of clear clinical data showing benefits, he added.
The exercise group received a multi-stage, guided exercise
program that began with 36 supervised training sessions with a goal of 30 minutes
of exercise three times a week. At the 18th session, patients received a treadmill
or exercise bicycle for home use, learned how to monitor their heart rate during
exercise and were encouraged to try to complete five weekly exercise sessions
of similar intensity and 40 minute duration.
The 36 supervised exercise sessions were modeled on the
cardiac rehabilitation sessions provided to heart attack survivors, which are
usually covered by insurance, O'Connor said. Patients in the usual care group
received instructions based on the American College of Cardiology/American Heart
Association recommendation to perform 30 minutes of moderate intensity exercise
most days of the week.
An unusually high proportion of the patients received
optimal medical care with more than 90 percent of them getting evidenced-based
medical therapy for their heart disease. A significant number also had implantable
cardioverter defibrillators, said David Whellan, M.D., M.H.S., co-principal investigator
and associate professor of medicine (cardiology) at Thomas Jefferson Medical College
in Philadelphia, Penn.
"Thus, the findings from the study need to be interpreted
with the understanding that the improvement in outcomes were obtained while the
patients were receiving exceptionally high quality of care," Whellan said.
After three months in the study, 52 percent of the exercise
group were exercising at least three times a week for 40 minutes, a percentage
that held fairly steady through the first year and then dropped off slightly,
Whellan said. The median exercise time was maintained from 76 minutes per week
at three months to 74 minutes per week at one year. At the one-year follow-up,
25 percent of the patients in the exercise group reported completing five sessions
per week, he said.
"If you think about their degree of illness, the level
of training by these patients was impressive," Whellan said.
Forty percent of the trial participants were members
of minority groups and 28 percent were women. O'Connor credited the diversity
to the medical centers involved and the U.S. government's encouragement for including
populations that have traditionally been under represented in medical trials.
The average left-ventricular ejection fraction (LVEF)
in the study was 25 percent, indicating moderate heart failure. More than half
of the participants had a history of blood vessel blockage and about 40 percent
had a history of heart attack, meaning the study has implications for a wide variety
of heart failure patients.
"This is the most definitive study to guide policymakers, physicians, healthcare
providers and health systems in regard to recommendations for exercise training
in patients with heart failure," O'Connor said.
Co-authors include: Kerry L. Lee., Ph.D.; Steven J. Keteyian,
Ph.D.; Lawton S. Cooper, M.D.; Stephen J. Ellis, Ph.D.; Eric S. Leifer, Ph.D.;
William E. Kraus, M.D.; David S. Rendall, P.A.-C; Nancy Houston-Miller, R.N.,
B.S.N.; Jerome L. Fleg, M.D.; Robert S. McKelvie, M.D.; Lawrence Fine, M.D.; Kevin
A. Schulman, M.D.; and Ileana L. Pina, M.D. Individual author disclosures are
available on the abstract.
This study was funded by the National Heart, Lung, and
Blood Institute with additional funding from General Electric and Roche Diagnostics.
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